Following the pattern of naming large multiples of ten (as in million, billion, trillion, etc.), zillion, bajillion, squillion, gazillion, jillion, kajillion, etc. are indefinite and fictitious large numbers, or units of imprecise measurement, used in exaggeration. The size is dependant upon the context to which it is used, but can typically be considered large enough to be unfathomable by the average human mind.

Typically, these words are used in a humorous context, or used by for instance schoolchildren in loose, unconfined conversation, when wishing to abstract at an unguessably large number, or to impress someone with the concept of an ambiguous numerical enormousness.

An adjective derived from zillion is zillionth. The other adjectives are similarly derived.

Since these are undefined numbers used in a colloquial context, they are not considered to have mathematical validity.

Each of these numbers is by no means considerably larger or smaller than any of the other ambiguous numbers but can be conceived of as such, due to personal preference. Various authors and other persons have set their own definitions as to amount and order of fictional and ambiguous numbers, often related to their experiences with juvenile schoolchildren and their offered explanations.

Example use

• That car must have cost a zillion dollars!
• the Zillions of Games software product.
• quantifying Scrooge McDuck's capital
• From the television series Futurama, episode 1X06, "A Fishful of Dollars," where Fry is bidding for the last known can of anchovies in existence:

Fry: "One jillion dollars!" [the crowd gasps]

Auctioneer: "Sir, that's not a number." [the crowd gasps again]

See also

• Nicolas Chuquet
• Names of large numbers